Docs: clarify non-applicability of the tls_eccurve option to GnuTLS

diff --git a/doc/doc-docbook/spec.xfpt b/doc/doc-docbook/spec.xfpt
index 47341b163ba1d9e0be2c5f22b42d3533219c7c46..c69e45c391514af127b3f09c194309071cedd224 100644 (file)
--- a/doc/doc-docbook/spec.xfpt
+++ b/doc/doc-docbook/spec.xfpt
@@ -17136,7 +17136,8 @@ acceptable bound from 1024 to 2048.
 
 .option tls_eccurve main string&!! &`auto`&
 .cindex TLS "EC cryptography"
-This option selects a EC curve for use by Exim.
+This option selects a EC curve for use by Exim when used with OpenSSL.
+It has no effect when Exim is used with GnuTLS.
 
 After expansion it must contain a valid EC curve parameter, such as
 &`prime256v1`&, &`secp384r1`&, or &`P-512`&. Consult your OpenSSL manual